Question

Find the maximum value of y = -2(x - 4)2 - 6.

Answer 1

y = -2(x-4)2-6

= -4(x-4) - 6

= -4x + 16 -6

y = 10- 4x

now if x is positive, x >= 0

then max value of y will be when x will nr minimum

so max y = 10- 4×0 = 10

so y = 10 at x =0 for x >=0

if x < 0 then

y will be increasing as x gets increase towards more negative. so max of y will be decided when x reaches to max negative.